btrfs hanging since 3.16-rc3 or so

Norbert Preining
2014-07-15T13:46:26Z

Dear all

(please keep Cc)

Since 3.16-rc3 or so I regularly get btrfs hanging in some transations.

Usually during apt-get upgrade or some other large file operations
(cowbuilder building of packages).

The log files give me for loads of processes things like:
[ 6236.746546] INFO: task aptitude:22775 blocked for more than 120 seconds.
[ 6236.746547] Tainted: G W O 3.16.0-rc5 #27
[ 6236.746548] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 6236.746549] aptitude D ffff8800b21a3868 0 22775 22709 0x00000000
[ 6236.746550] ffff88003644fd10 0000000000000082 ffffffff81a15500 ffff88003644ffd8
[ 6236.746552] ffff8800b21a3430 0000000000011c00 ffff880147da9c30 ffff880147da9c30
[ 6236.746553] ffff88003644fd58 ffff880034b3ed48 ffff880034b3ed38 ffff88003644fd20
[ 6236.746555] Call Trace:
[ 6236.746557] [<ffffffff81585b4a>] schedule+0x64/0x66
[ 6236.746560] [<ffffffff811bb22e>] btrfs_wait_logged_extents+0xa4/0xdc
[ 6236.746561] [<ffffffff810635c1>] ? finish_wait+0x5d/0x5d
[ 6236.746564] [<ffffffff811d9489>] btrfs_sync_log+0x5ef/0x8a2
[ 6236.746567] [<ffffffff811b43cf>] btrfs_sync_file+0x21b/0x24d
[ 6236.746569] [<ffffffff811b43cf>] ? btrfs_sync_file+0x21b/0x24d
[ 6236.746571] [<ffffffff8110db8a>] vfs_fsync_range+0x1c/0x1e
[ 6236.746574] [<ffffffff810d1681>] SyS_msync+0x15d/0x1ea
[ 6236.746575] [<ffffffff81588712>] system_call_fastpath+0x16/0x1b

THis is aptitude, but I have all the other tasks accessing the disk
hanging, too.

This time, issueing a Sysrq-s for emergency syncing did the laptop
out of the hang.

Hardware: Sonly VAIO Pro 13
Distribution: Debian/sid
self compiled kernel, config on request.

Please let me know if there is anything else I can provide.

Thanks a lot

Norbert

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PREINING, Norbert http://www.preining.info
JAIST, Japan TeX Live & Debian Developer
GPG: 0x860CDC13 fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13
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